21747132 has 36 divisors (see below), whose sum is σ = 59970456. Its totient is φ = 6589920.

The previous prime is 21747127. The next prime is 21747133. The reversal of 21747132 is 23174712.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a junction number, because it is equal to n+sod(n) for n = 21747096 and 21747105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21747133) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27063 + ... + 27854.

It is an arithmetic number, because the mean of its divisors is an integer number (1665846).

Almost surely, 2^21747132 is an apocalyptic number.

21747132 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21747132 is an abundant number, since it is smaller than the sum of its proper divisors (38223324).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21747132 is a wasteful number, since it uses less digits than its factorization.

21747132 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54938 (or 54933 counting only the distinct ones).

The product of its digits is 2352, while the sum is 27.

The square root of 21747132 is about 4663.3820345324. The cubic root of 21747132 is about 279.1262387832.

The spelling of 21747132 in words is "twenty-one million, seven hundred forty-seven thousand, one hundred thirty-two".